muttest

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About

muttest is ranked #7 of 25 in mutation testing tools on Inferse. It runs on Linux, macOS, Windows.

Compared on mutation testing tools

Free plan: Yesjakubsob.github.io
Supported languages: Rjakubsob.github.io
Test frameworks: testthat; cucumberjakubsob.github.io
Incremental analysis: Yesjakubsob.github.io
Surviving mutant reports: Yesjakubsob.github.io
Mutation quality gate: Yesjakubsob.github.io
Mutation operators: Binary operators; arithmetic operators; comparison operators; logical operators; boolean literals; NA/NULL literals; numeric literals; string literals; condition negation; function-call names; index increments/decrements; explicit return valuesjakubsob.github.io

Facts

Purpose: muttest mutates R code and runs tests to measure how often the tests catch those changes.jakubsob.r-universe.dev · 3 Oct 2026
Mutation score: The package reports a percentage score for how often tests catch mutations.jakubsob.r-universe.dev · 3 Oct 2026
Configurable mutations: Users choose what code changes to make and where to make them.jakubsob.github.io · 3 Oct 2026
R test workflow: The maker describes muttest as mutation testing for R and shows tests under the testthat framework.jakubsobolewski.com · 3 Oct 2026
Mutation examples: The maker’s examples include changing comparison operators to expose untested boundary cases.jakubsobolewski.com · 3 Oct 2026
Reporting: The package includes HTML and JSON reporting.jakubsobolewski.com · 3 Oct 2026
Parallel execution: The maker’s July 2026 update describes parallel execution as a muttest capability.jakubsobolewski.com · 3 Oct 2026
CI: The documentation index links a guide to running muttest in CI, including GitHub Actions and score badges.jakubsob.r-universe.dev · 3 Oct 2026
Install: The package page provides an R install.packages command using the maker’s r-universe repository and CRAN.jakubsob.r-universe.dev · 3 Oct 2026
Supported build platforms: The package page lists successful checks for Linux, macOS, Windows, and WebAssembly targets.jakubsob.r-universe.dev · 3 Oct 2026
Requirements: The documentation index lists testthat among muttest’s dependencies.jakubsob.r-universe.dev · 3 Oct 2026
Maker: The maker identifies himself as Jakub Sobolewski, a software engineer specializing in R and Shiny.jakubsobolewski.com · 3 Oct 2026
File feedback: The tool reports which files need stronger assertions.github.com · 4 Oct 2026
Mutators: Available mutators include operator, boolean, NA or NULL, function-call, string, numeric, index, condition, negation, and return-value changes.github.com · 4 Oct 2026
Preset mutators: Preset collections cover arithmetic, comparison, logical, boolean, NA, numeric, index, string, and condition mutations.github.com · 4 Oct 2026
HTML report: The package documentation lists a CI vignette describing how to run mutation tests on every push, add a score badge, and enforce thresholds.github.com · 4 Oct 2026
Intended users: The project describes mutation testing as a way to find weak assertions in test suites, including suites generated with LLMs.github.com · 4 Oct 2026
Package type: muttest is an R package for mutation testing.github.com · 4 Oct 2026
License: The package is licensed under MIT plus a LICENSE file.mirror.clarkson.edu · 4 Oct 2026
Runtime requirement: The CRAN package listing states that muttest depends on R version 4.1.0 or later.stat.ethz.ch · 4 Oct 2026
Maintainer: The CRAN package listing names Jakub Sobolewski as author and maintainer.stat.ethz.ch · 4 Oct 2026
Release: The CRAN listing shows version 0.3.0, published July 21, 2026.stat.ethz.ch · 4 Oct 2026